Evaporation rate in the garage in fl.

[erc111]

Reposted from reef disc.

OK, I guess I don't understand thermodynamics.
I had to move my 120g to the garage after an incident when the auto topoff failed and I flooded the hardwood floors. The wife was none too happy.

Anyway I thought that in my garage in FL, 100f afternoon temps, that even with a chiller keeping the temp at 78f the evap rate would be higher than in the house.

Appears not so. I can't seem to get the right amount of flow thru the topoff. it is probably half what I had in the AC house, where it was about 1 drop/sec, about 5g/3days.
Same setup, 2 250w halides,2 96w pc-o3, computer fans in the full canopy but 1/3 and back open with eggcrate.

I use a 5g bucket with an agualifter pump and a ball valve.
When I turn it low than that the kalk clogs the valve.

Not looking for help about topoffs.

Just wondering about the thermodynamics.

Thanks,

 

[Cuervo]

I live in FLA also.

I imagine the reason for the difference is that the house AC was lowering the humidity by ALOT, which helps with evaporation.

The outside air on the other hand is quite humid, which would lower evaporation. If the garage is not well ventilated, then you might be saturating the air, which would reduce evaporation even more.

If you're stuck with the garage, you could try some ventilation, combined with fans over the tank. Maybe even go for a dehumidifier.

If I'm not mistaken, the big impact with respect to temperature is how much water vapor the air will actually hold before it is saturated (100% humidity). The higher the temp, the more water vapor the air will hold. That's why on early florida mornings, when the temp has recently dropped drastically, it gets so foggy outside.

 

[erc111]

Thanks, but it's not really a problem. I was just curious. Probably is the humidity. Notice I said I have a chiller and the tank stays 78F(+2,-1) and the garage is well ventilated.

I just thought with a lower temp than before and the temp differential , I would get more not less evap

I'm retired so the main garage door is open all day and left cracked at nite.
No cars in the garage just my workshop, tank and lots of stuff not kept in the house, but it is hot and humid, just like outside.

The tank actually seems to be doing much better outside.
Cleaner air, more stable/ lower temp.

 

[Cuervo]

You could try the angle of explaining that having the tank in the garage is going to drive up heating/cooling costs

Well.. unless you like having it out there.

Glad to hear it's doign well though. I bet this fall/winter you'll get a much better evap rate when the temp/humidity go down.

 

[erc111]

Yea, it certainly will drive up my electric bill. 3500sq.ft. house-$500 last month, but electricity cost have gone up. Don't know what portion the tank is.

I was forced to move it to the garage when I had a top-off float fail. Flooded the hardwood floors in the living room. Ruined about 100 sq. ft. Wife said get it out of here.

Now I actually do like it there. No worry about spills, even normal ones as when changing water.
Plus , the garage door leading to the house is the main entrance. It actually gets noticed more.

 

[BeanAnimal]

Very simple....

Heat is only a small factor in evaporation. The AC unit keeps the house humidity low and aids in evaporation of the tank water. In the garage, the air is likely very humid and the airflow over the tank likely less. Both of these factors mean less evaporation.

The chiller is going to have to work a lot harder without the evaporation and lower ambient room temperature. This will drive you electric bill higher. Keeping the garage door open may also have some effect on the overall AC usage.

Enjoy.

 

[erc111]

Disagree, not so simple, while the humidity is definitly much higher and is probaobly the cause of less evap, the air flow over the tank is is much greater than in the house.
The windows are open and i have a 20 in. fan blowing the hot air from the chiller directed outside. And there is a breeze thru the garage 90% of the time.
I also have 2 computer fans in the hood blowing on the halides.
BTW, don't care about the electric usage.

Also , 6.5 yrs in the USN, 1976- 1983. 4.5 yrs. on a frigate chasing russian submarines. We won the cold war. Not so simple now!

 

[BeanAnimal]

Evaporation is directly proportional to the humidity of the air at the air/water interface. You may have "more" air moving in the garage, but the air at the surface of the water is much more humid than the conditioned air in the house. The temperature of the air is not really a factor here, because the water temperature is a constant (inside the house our outside). Fans will help a little but replacing wet air with wet air is nowhere near as efficient as replacing that wet air with dry air.

Thank you for your service

 

[erc111]

I agree, but why would I want to add fans?, this may increase evap but why would I want to increase evap?

 

[Cuervo]

I thought your original problem was that you needed to Evap more water so you would have more flow through the Kalk reactor.

The only other reason I can think of to add fans and increase evap is that it's cheaper to cool the tank this way instead of with the chilller working over time. You already said electricity cost isn't an issue, so this one is out.

 

[erc111]

Ha. Your're right. Lost my train of thread.
However, this weekend i replaced all the tubing and cleaned the ball valve with vinager. Working OK now, albeit it is running slower cause of the evap rate.
I'll just have to clean the ball valve more often.